Charger, battery monitor, float charge level

[Ami P]

Setup: 2 new golf cart batteries, in series 12V, 220AH [at]20H rate, Schauer 6amp automatic 4 stage charger, Xantrex LinkLite monitor, OEM 30Amp converter (13.8V "float" charge at 0.2 Amp)

Issue: the charger shows the batteries as full, the float charge is 13.4V. The LinkLite monitor shows a drain of 0.1 Amps, which is what the LinkLite monitor itself is using. This drain is cumulative (0.1 Amps per hour,) so:

Question 1: is the converter's 13.8V too high as a "float charge?"

Question 2: assuming that the charger will eventually switch to the absorption stage, is it normal to show "full" despite the small drain? LinkLite keeps asking for a "synch."

Thanks,
Ami

[kevin61]

[b]Setup: 2 new golf cart batteries, in series 12V, 220AH [at]20H rate, Schauer 6amp automatic 4 stage charger, Xantrex LinkLite monitor, OEM 30Amp converter (13.8V "float" charge at 0.2 Amp)

[b]Issue: the charger shows the batteries as full, the float charge is 13.4V. The LinkLite monitor shows a drain of 0.1 Amps, which is what the LinkLite monitor itself is using. This drain is cumulative (0.1 Amps per hour,) so:

[b]Question 1: is the converter's 13.8V too high as a "float charge?"

[b]Question 2: assuming that the charger will eventually switch to the absorption stage, is it normal to show "full" despite the small drain? LinkLite keeps asking for a "synch."

Thanks,
Ami

Ami,

The power draw sounds normal to me. My similar system has phantom loads of anywhere from .1 to 0.3 amps. this includes normal line losses from connections/wire etc as well as stereo memory, gas detector etc.

Your monitor probably has set parameters that it uses to consider the battery full. When the battery meets these criteria it is considered "full". Your charger may have slightly different parameters.

If it is like my XBM monitor the "sync" is probably the manual mode to sync your battery with the monitor. Not sure for your monitor but I have to press the forward and reverse arrows for 3 seconds to get my monitor to sync with my battery.

I do this a few times a year, usually after I have fully charged the battery, equalized it and then let it sit for a day.

Since I have just manually charged the battery I know for sure that it is full. When I sync it I am telling the monitor this is what I mean by "full"

I do this every so often as the monitors will start to "wander" over time.

If you have not already done so you probably also need to tell your monitor the size of battery bank you are using

If I am not mistaken it is your charger that is providing the float charge of 13.8 volts, not your converter. I am not sure but from your wording the Converter may be also acting as a charger. (I am unfamiliar with this converter) If this is the case my guess is that you may have two charging sources on your battery. The battery charger and the converter.

Normal charging procedure is bulk charge to get the battery up to approx. 90%, Absorption charge for the last 10% and then float charge.

As you drain your battery by using appliances either directly or through your converter the charger will sense the draw and will charge your battery accordingly. If you are drawing a lot it will charge at its max (6 amp?) If you are drawing only a bit of power it may charge at 1 amp.

Normal float charges vary with appliances. Different battery manufacturers will also recommend different float levels. My Solar setup was set for 13.7 volts while my Xantrex Truecharge floats at `13.4 volts. You may have the ability to change these parameters on your charger and converter.

If you can send me the links to a pdf. file of your particular battery charger and your converter operators manuals I can give them a quick read.

[Ami P]

Kevin,
The factory converter/charger is the original OEM in the UHaul VT 16 of 1985. I do not have a manual. I think it's 30amps. I also know that it puts out 14.5+V when needed, I already gave you the lower "float" settings. I will try to find out the actual coverter/charger model.
Thanks,
Ami

(written earlier today 7/9/09)
The monitor settings are correct and were input: charger float charge for auto-synch= 13.4V, battery capacity = 220AH, low battery setting 12.1V or 50%, etc.

I am questioning the usefulness of my new automatic charger IF the built-in OEM, factory converter/charger voltage is not too high at 13.8 V. I thought that float voltage should not rise above 13.5 V. I usually use the converter for the bulk and absorption stages and I assumed that although it produces 13.8 V, the amperage is only 0.2 at its lowest.

The idea behind buying the automatic multi-stage modern charger was that is will keep the battery in steady float mode, spit-spot ready, but is it really needed if the converter/charger is doing its job? It seems that the battery is not being charged at 13.4V since it shows the phamtom load and the cummulative used AH.

[Ami P]

Kevin,
The factory converter/charger is the original OEM in the UHaul VT 16 of 1985. I do not have a manual. I think it's 30amps. I also know that it puts out 14.5+V when needed, I already gave you the lower "float" settings. I will try to find out the actual coverter/charger model.
Thanks,
Ami

[Larry C Hanson]

Hello Ami, Here is a useful source of information for dealing with
with deep cycle batteries http://www.windsun.com/Batteries/Battery_FAQ.htm

Larry H